The existence of the Sidoarjo mudflow is a history and through a long process, occurring since May 29, 2006 and until now there are no signs of stopping. The center or point of the Sidoarjo mudflow is located in Siring Village, approximately 200 meters from the Banjar Panji -1 gas drilling well owned by PT. Lapindo Brantas in Renokenongo Village, Porong District, Sidoarjo Regency, East Java Province. In the latest developments, the phenomenon of hot mudflow is believed to be the activity of forming a mud volcano. Since the enactment of Presidential Regulation no. 21 of 2017, the duties and functions of the Sidoarjo Mudflow Management Agency have been transferred and implemented by the Ministry of PUPR in accordance with the Regulation of the Minister of PUPR no. 5 of 2017 by forming the Sidoarjo Mudflow Control Center. The duties and functions are transferred and implemented by the Ministry of PUPR. In connection with the subsurface conditions of the mud retaining embankment which has a very low bearing capacity, causing frequent landslides (sliding). In addition, over time, the weakening of the embankment structure has resulted in seepage at several points on the embankment body. Based on this, handling is needed to restore the function of the mud retaining embankment through the work of Improving/Strengthening the Mud Retaining Embankment which is supervised by the Supervising Consultant through the Mud Retaining Embankment Improvement/Strengthening Supervision work package with the 2023 State Budget funds for the Sidoarjo Mud Control DIPA SNVT.

The purpose of O and P activities is to carry out operation and maintenance activities of the infrastructure and facilities of embankments and spillways so that they can function properly, with the hope of maintaining the service function of embankment reinforcement and preventing flooding and increasing its benefits to support social, economic, cultural and regional development activities. Maintenance is intended to maintain the quality of materials or construction components in a building. Repair and Reinforcement are intended to prevent the spread of deterioration of materials and to restore them to their original condition.

Basic Concepts of Maintenance & Repair:

a. Materials or construction will experience a decrease in quality along with the age of the building. b. Maintenance must be carried out in a planned manner according to the specifications of the materials used and adjusted to environmental conditions that may affect the life of the building
c. Ignoring the maintenance plan will expand and worsen the level of damage to materials or construction components.

d. The selection of quality materials and quality of work, relatively increases the service life will be longer to reduce the maintenance schedule interval.

e. Repair work can be carried out after knowing exactly the cause of the damage and the cause has been addressed.

Inspection accompanied by evaluation of the data records of the monitoring instrumentation results will be able to provide a complete picture of the condition of the mud retaining embankment, both visible on the surface and inside the embankment. All reading and measurement results as well as detailed explanations/descriptions needed to provide an accurate picture of the condition of the reservoir at the time of the inspection must be recorded and archived properly throughout the life of the embankment. Embankment inspections are carried out routinely, periodically and annually. Depending on the purpose and conditions to be obtained from the results of the embankment inspection. Inspection of the building function is simply to answer the question of whether the building can function as planned? While the inspection of the building structure is more directed at whether the construction quality is in accordance with the required technical specifications? Two building inspection paradigms will be introduced to facilitate evaluation and make decisions whether the building is suitable for operation? . In simple terms, the functional inspection of dam buildings can be grouped into 4 categories (reff. World Bank irrigation network inventory work by JICA Consultants, 2002), namely: · Buildings are functioning well · Buildings can still function with constraints · Buildings cannot function well · Buildings cannot function at all · Under certain conditions, dam buildings are in good condition in terms of construction/structure, but cannot function according to plan. To overcome this situation, a review of the arrangement is needed, if this is not possible, the building will be completely renovated.